Abstract
Identifying the genetic determinants underlying plant-plant interactions is key for understanding plant community dynamics, both in natural and agronomical systems. This report unveils the complex genetic architecture of plant-plant interaction effects on aerial biomass and septoria tritici blotch severity in varietal mixtures of wheat, using co-genome-wide association study. Fifty-four signi cant allelic interactions between distinct loci were identi ed, with half involving hub loci. Some inter-individual epistasis might be related to the shade-avoidance syndrome. Our results underscore the critical role of allelic interactions between inter-individual loci in shaping plant phenotypes and community dynamics, offering new perspectives to optimize varietal mixtures.